I'm a delivery driver driving a ford falcon Ute with canopy and tow bar and regularly park with 6 inches behind me and 12 inches in front and yes you can get out. It might take 3 goes going back and forward but pretty easy. You get used to it with parks the average size of a small Japanese car.. Have also been guilty of bending in a few number plates with the tow bar.

If you park with 6 inches behind you then that doesn't leave 12 inches in front of the person behind you, it leaves them with 6. You robbed them. You bad man. This means if someone with your theory comes along, you will be left with 6 inches front and back and have to perform the previously aforementioned 749 point manoeuvre.